import sys
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0

n = int(readline())
dic1 = {
    4:8,
    6:7,
    8:6,
    10:5,
    12:4,
    14:3,
    16:2,
    18:1,
}
for i in range(4,19,2):
    if i*100 <= n < (i+2)*100:
        print(dic1[i]) import sys sys readline = sys.stdin.buffer.readline readline sys.stdin.buffer.readline sys.stdin.buffer sys.stdin sys stdin buffer readline def even(n): return 1 if n%2==0 else 0 even n n n = int(readline()) n int(readline()) int readline() readline dic1 = {
    4:8,
    6:7,
    8:6,
    10:5,
    12:4,
    14:3,
    16:2,
    18:1,
} dic1 {
    4:8,
    6:7,
    8:6,
    10:5,
    12:4,
    14:3,
    16:2,
    18:1,
} 4 4 8 6 6 7 8 8 6 10 10 5 12 12 4 14 14 3 16 16 2 18 18 1 for i in range(4,19,2):
    if i*100 <= n < (i+2)*100:
        print(dic1[i]) i range(4,19,2) range 4 19 2 if i*100 <= n < (i+2)*100:
        print(dic1[i]) i*100 <= n < (i+2)*100 i*100 <= n i*100 i 100 n (i+2)*100 i+2 i 2 100 print(dic1[i]) print dic1[i] dic1 i def even(n): return 1 if n%2==0 else 0 def even(n): return 1 if n%2==0 else 0 even readline = sys.stdin.buffer.readline sys.stdin.buffer.readline readline n = int(readline()) int(readline()) n dic1 = {
    4:8,
    6:7,
    8:6,
    10:5,
    12:4,
    14:3,
    16:2,
    18:1,
} {
    4:8,
    6:7,
    8:6,
    10:5,
    12:4,
    14:3,
    16:2,
    18:1,
} dic1
import sys
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0

n = int(readline())
dic1 = {
    4:8,
    6:7,
    8:6,
    10:5,
    12:4,
    14:3,
    16:2,
    18:1,
}
for i in range(4,19,2):
    if i*100 <= n < (i+2)*100:
        print(dic1[i])